1. Field of Invention
This invention relates generally to safety devices for industrial plants. Specifically, this invention is a safety blinding device used to cover the openings of pipes or industrial vessels while such pipes and vessels, or adjacent pipes and vessels, are taken off-line for maintenance and cleaning.
Blinding devices ensure that pipes and vessels being cleaned or maintained are completely cut off from the remainder of the industrial process. By cutting them off from the process, the hazardous fumes or substances normally present in the process flow are not injected into the vessel or pipe being maintained. Blinding is particularly critical if the workers performing the cleaning or maintenance (of the vessel or pipe) would be exposed to the hazardous substances were it not for the blinding devices.
2. Related Art
Devices that are able to temporarily cut-off pipelines, vessels, and other industrial containers and elements are known to the prior art. Illustrative of such devices are U.S. Pat. No. 1,502,444 issued to Stillwaggon on Jul. 22, 1924; U.S. Pat. No. 2,566,343 issued to Livesay on Sep. 4, 1951; U.S. Pat. No. 2,645,244 issued to Klickman on Jul. 14, 1953; U.S. Pat. No. 4,014,367 issued to Milo on Mar. 29, 1977; U.S. Pat. No. 4,351,446 issued to Madden on Sep. 28, 1982; U.S. Pat. No. 4,848,458 issued to Holdsworth et al. on Jul. 18, 1989; U.S. Pat. No. 5,184,608 issued to Hale, III on Feb. 9, 1993; U.S. Pat. No. 5,494,079 issued to Tiedemann on Feb. 27, 1996; and U.S. Pat. No. 5,582,211 issued to Monson on Dec. 10, 1996.
The Klickman '244 patent, the Livesay '343 patent, and the Monson '211 patent each disclose a typical prior art blinding device. The typical prior art blinding device generally comprises a circular body and at least one extension leg. The circular body is large enough to fully cover the opening of the relevant pipe, vessel, container, or industrial element. The extension leg extends radially from the circular body. In operation, if a first industrial element (such as a vessel or pipe) needs to be taken off-line for maintenance purposes, the first industrial element must be cut-off from its adjacent industrial element (such as an adjacent pipe or flange) and the remainder of the process. The blinding device is positioned between the flange of the first industrial element and the flange of the adjacent industrial element so that the circular body covers the openings of both the first and adjacent industrial elements. The extension leg must be sized and constructed so that it clearly sticks out from within the flanges once functionally positioned therebetween. The blinding device is held in place by screwing threaded bolts through the flange bolt holes of both the first and adjacent industrial elements. Thus, the blinding device is caught between the flanges of the first and adjacent industrial elements. A colorful tag is then attached to the extension leg in order to warn workers that the blinding device should not be removed. Notably, the blinding device itself is normally not attached to the flanges but merely compressed therebetween.
Problems typically arise when both the first and adjacent industrial elements are concurrently taken off-line for maintenance. Unfortunately, the blinding device is sometimes left off of both industrial elements when the industrial elements are brought back on-line. In this case, if the first industrial element is not ready to be on-line at the same time as the adjacent industrial element, process flow or other fumes may flow from the adjacent industrial element into the first industrial element endangering the lives of any people working in or around the first industrial element.
It would thus be beneficial to the prior art to provide a blinding device that attaches to the flange of the relevant industrial element and is not just compressed between flanges. It would also be beneficial to the prior art to provide a blinding device that is attachable to the flanges of either or both of the relevant industrial elements. In order to ensure that it is not mistakenly removed at any point, the prior art would also benefit from a blinding device that can be locked into place. It would be a further benefit to the prior art to provide a blinding device that fits various sizes and pressure ratings of pipes and other industrial elements. In addition, it would be beneficial to the prior art to provide a blinding device that can enable both sealing blinding, in which a tight seal is achieved between the blinding device and the relevant flange, and spacer blinding, in which a spacer with holes is positioned between the blinding device and the relevant flange.